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【 introduction 】 select hydraulic control valve to consider many factors, such as, valve control characteristic, stability and oil mouth size, shape size, installation, connection and the way of manipulation). Select from the product samples or catalogue.
　　
Function and performance requirements:
　　
Pressure reducing valve used to reduce the pressure of a primary circuit in the system.Reduce the discharge pressure and constant pressure reducing valve is called fixed value output pressure reducing valve;Make its export pressure with a certain load is determined by the difference of constant pressure reducing valve is called differential pressure reducing valve;Make it a certain amount of pressure reducing valve inlet pressure and outlet pressure ratio is called the constant ratio pressure reducing valve.Claim to the fixed value output pressure reducing valve is: no matter how inlet pressure changes, outlet pressure should be able to maintain a constant, and is not affected by the change in the flow through the valve.For poor or constant ratio pressure reducing valve, insist on, no matter how inlet pressure and outlet pressure should make constant pressure difference or their ratio constant.
　　
Note for the choice of hydraulic control valve:
　　
1, the actual flow of hydraulic valve
　　
Actual flow hydraulic valve associated with oil series, in parallel, series oil flow equal everywhere;At the same time working in parallel oil flow rate is equal to the sum of each oil flow.Also made for the system of the single hydraulic cylinder piston rod) pay attention to the piston overhang and inside shrink when the flow of oil return: when retracted rodless cavity oil return with overhanging rod oil return cavity of the flow ratio of the longitudinal and the ratio of the two cavity area equal.
　　
2, rated pressure of the hydraulic valve and rated flow
　　
The pressure rating of the hydraulic control valve and the rated flow generally should be used instead of pressure and flow.For high reliability requirement of system made by valve rated pressure should be higher than that of its use.If the rated pressure and flow pressure and rated flow is less than using a longitudinal, easy cause hydraulic clamping and hydraulic power and harmful effect on the quality of valve work;To sequence valve and relief valve in the system made by the through flow should not be far less than the rated flow) or are prone to vibration or other unstable phenomenon.For the minimum flow valve) should pay attention to its stable flow.
　　
3, the installation of the hydraulic valve connection
　　
Due to the installation of the valve connection way for the subsequent design of hydraulic device structure has a decisive influence). So choosing hydraulic valve to hydraulic control device of integrated way to accomplish know fairly well.For example adopts hydraulic valve plate connection) valve can be installed on the oil or oil circuit boards). On the one hand, facilitate system integration and hydraulic equipment design reasonable). On the other hand, replacing hydraulic valve does not need to remove the tubing made more convenient installation and maintenance;If the need to be studied according to the pressure and flow rate of longitudinal superposition valve superposition valve series selection of spectrum, etc.
　　
4, the choice of direction control valves
　　
For the simple structure of ordinary check valve). Main attention should be paid to the reasonable choice of opening pressure: a low opening pressure) can reduce the flow resistance losses through one-way valve;But) to be used back pressure valve check valve made by its opening pressure is higher). To ensure sufficient back pressure.For hydraulic controlled check valve). In addition to this kind of directional valve related matters needing attention in the outside). In order to avoid causing the abnormal vibration and noise of the system) should also pay attention to the reasonable choose the way of pressure release: when back pressure is the export of hydraulic controlled check valve made by appropriate chooses leaked type drainage type within other information). Optional.
　　
In addition, it is worth noting that if in the process of gradual damage to the valve, namely before failure, and set up a regular detection mechanism, the valve shall be loss preventive maintenance on a regular basis, timely detection and repair the fault before the minor damage, can avoid the fault formation, veterinarian the valve fault impact on enterprise production to a minimum.